The positioning of a carrier element implemented as a plate is already described in DE-OS No. 33 45 877. The carrier plate shown there has the task of forming a support plane upon the transport carriage for an object to be transported, for exemple a workpiece or a pallet upon which the work piece is already located in a certain fashion. The carrier element need not be a plate. In general it can be formed by a suitable stand or the like which has at least three support points, by which a plane is defined.
A possible can be a frame which is formed by two girders or rails connected to one another via two transverse struts, whose surface lies in a common plane and serves as a support for pallets or the like. The necessity for such accurate positioning of the carrier element and its support plane on the transport carriage arises particularly in connection with pallet transport and transfer means in automatic processing systems, as are known, by way of example, from DE-PS No. 31 01 661 or the DE-GM No. 78 35 449.
Here, the pallets with the work pieces are to be transported back and forth by the transport carriage and transferred between an assembly and a processing station, and/or a storage station. The transfer can take place by means of the drive or transport and guidance means described there. The support plane of the of the carrier element on the lifting means of the transport carriage can be brought into the position required for the transfer of the objects, e.g. workpieces or pallets, only with a limited accuracy of about plus/minus 25 mm.
In many cases this does not suffice for the attainment of the desired machining accuracy of the objects or the workpieces on the pallets. The means which have previously been developed for the adjustment of the support plane of the carrier element forming the support plane of the lifting device (DE-OS No. 33 45 877) require an additional stand ahead of the processing station, are extensive, and require additional space for the approach of the transport carriage to the station.